1. Field of the Invention
The present invention relates to an image processing method and an image processing apparatus arranged to detect a two-dimensional code from an image.
2. Description of the Related Art
As two-dimensional code detection methods, the following technologies in related art have been proposed.
U.S. Pat. No. 5,691,527 describes such a technology that an image is scanned in a certain direction, a signal of a symbol for the detection is detected on the basis of the scanning line signal pattern, and a two-dimensional code is detected from the image.
Also, US Patent Publication No. 2002/0051573 describes such a technology that an image is divided into a grid with blocks of M×N pixels, an area where blocks assumed to function as a two-dimensional code continuously exist is detected, and the area is extracted as a two-dimensional code area.
In addition, U.S. Pat. No. 6,671,422 describes such a technology that an image is divided into small areas, a small area with a high complexity is found on the basis of gray scale of the small areas, and a rough position of a two-dimensional code is determined.
According to the methods proposed in the related art, in a case where the two-dimensional code is rotated or a plurality of two-dimensional codes are included in the image, it is difficult to detect the symbol for the detection.
Also, according to the method of dividing the image into the small areas as described in U.S. Pat. No. 6,671,422, the size of a detected two-dimensional code relies on the size of the small area. Thus, it is difficult to detect the code in a case where two-dimensional codes with different sizes are included in the image.